Abstract

Aim: To assess the influence of different variables on the survival of class II glass ionomer cements (GIC) in a clinical study among 6–7 year old schoolchildren in and around Dar es Salaam, Tanzania. Methods: 217 children were randomly divided into three groups. In the conventional group, Class-II cavities were excavated with burs, in the ART group they were excavated with hand instruments and in the Carisolv™ group excavation took place with a chemical solution and special blunt hand instruments. The preparations in all groups were restored with hand mixed GIC (Fuji IX) by 4 operators. After restoration, residual caries and cervical gaps were assessed on bite-wing radiographs. The quality of the restorations was established and the survival rate determined in two subsequent evaluations. Results: 195 children (90%) were present at the first evaluation which took place after 7 months and 194 (89%) were present at the second evaluation, after one year. At the first evaluation the survival rate of the ART-restorations was 38%, of the conventional restorations 50%, and of the Carisolv™ restorations 35%. Survival rates at the time of the second evaluation were 30%, 42% and 28% respectively. The differences between the three treatment groups were, however, not significant (p=0.200 at t=1and p=0.247 at t=2). In the first evaluation 161 bitewings were available of the 195 restorations, while for the second evaluation 130. There was no significant relation between residual caries and the success/failure rate (p=0.140 at t=1 and p=0.201 at t=2). Also, cervical gaps appeared to have no relation with the failure rate (p=0.057 at t=1 and p=0.833 at t=2) However, together those variables have a significant influence on the survival rate (p = 0.025). Conclusion: The combination of two variables (residual caries and cervical gaps) has considerable influence on the survival rate of class II GIC restorations compared to each variable alone.